public function index()
 {
     $configuration = isset($this->params['configuration']) ? $this->params['configuration'] : null;
     if ($configuration !== 'default') {
         $assignments = new AssignmentsObject($configuration);
         $this->params['assignments'] = $assignments->get();
         $this->params['options'] = $assignments->assignmentOptions();
         $this->params['assignment'] = $assignments->getAssignment();
     }
     return $this->container['admin.theme']->render('@gantry-admin/pages/configurations/assignments/assignments.html.twig', $this->params);
 }